Process for preparing alkyl sulphate liquors



Jan. 27, 1942.

G. A. PERKINS ET AL PROCESS FOR PREPARING ALKYIJ SULPHTE LIQUORS Filed April 24, 1951 CRA cffso HyaPocARso/vs ARQMA T/c HyoRacARaa/vs' 5- (A fren/v Ara/v 5- CARBa/v 5 02 55cm/pany A u AL CQf/OL ENTORSI Q ATTORNEYS Patented Jan. 27, 1942 UNITED STATES PATENT OFFICE PROCESS `FOR. PREPARING ALKYL SULPHATE LIQUQRS Granville A. Perkins, South Charleston, and John A. Davies; Charleston, W. Va., assignors, by mesne assignments, to Union Carbide and Carbon Corporation, a corporation of New York Applicatlon'April-M, 1931, Serial No. 532,678

14 The invention'is an improved process for preparing alkyl sulphate liquors from olene hydrocarbon mixtures.

carbons having four or more carbon atoms in` the molecule, and may be advantageously employed as a step in the preparation of secondary and tertiary alcohols having a .corresponding number of carbon atoms in the molecule..

Vapor-phase cracking of petroleum or petroleum fractions produces hydrocarbon mixtures containing a variety of saturated Aand unsaturated hydrocarbons. Mixtures of this type are preferred as the starting material for the process. It is an Aobject of our invention to utilize cracked hydrocarbon mixtures to form alkyl sulphate liquors in` such a manner as will resultl in the recovery of a large proportion of the constituents of the starting material.

The present invention avoids or mitigates this difliculty and its advantages will be apparent from the following description.

In general, the process comprises a physical separation of one or more fractions, substantially free from propylene and ethylene and from aromatic hydrocarbons,v from a mixture of "part of our invention. The fraction or fractions y cracked hydrocarbons. This may be accomplished by known methods of condensation and fractional distillation, which are no essential so obtained are then treated to remove ldiolelnes, such as butadiene, isoprene, cyclopentadiene and 2,3 dimethyl 1,3 butadiene. This removal is effected in a manner which does not destroy'the 'olenes present in the mixture, and which re- Another object is to provide an economical process for the formation of alcohols by means of our process for preparing alkyl sulphate liq'- uors.

Cracked hydrocarbon mixtures may contain parain hydrocarbons, olenes, dlolenes 'and aromatic hydrocarbons, together with lesser quantities of acetylene and hydrogen. Due to the practical limitations of ordinary methods of fractional distillation it is not feasible, by such methods, to isolate the rindividual oleflnes of higher molecular weight than propylene from a mixture containing these compounds. For example, butadiene cannot be separated from a mixture containing other four carbon atom hydro-- carbons by ordinary fractional distillation for the reason that it forms with n-butane a constant boiling mixture which boils very close to theboiling points of isobutylene and butene-l.

Previously known processes using the olefine hydrocarbons to form alkyl sulphate liquors have caused the diolenes and more reactive hydrocarbons contained in admixture with the olenes, to be removed as polymers. AThis is uneconomical because it not only renders the dioleflnes, so

polymerized, unt for further use, but, also, be-

cause it results in losses of the valuable olefines to some extent inasmuch as it is impossible to remove the diolenes by polymerization without moves the diolenes in a form vfrom which they may be easily regenerated.' The diolene-freed material is then treated with succssiveapplicaftions of sulphuric acid of suitable strength under "appropriate conditions of temperature and lpressure. These treatments provide alkyly sulphate liquors of both tertiary and secondary derivation.

substances less volatile than hydrocarbons having ve carbon atoms in the molecule, Were separated from a mixture of cracked hydrocarbons produced by the vapor-phase cracking of gas oil. One fraction contained principally hydrocarbons having four carbon atoms in the molecule, including butane, butene-l, butene-2, isobutylene and butadiene. This fraction will be hereinafter identified as the 4-carbon atom fraction.

The other fraction contained principally hydrocarbons having ve carbon atoms in themolecule, including pentane, pentene-l, pentene-Z, isopropyl ethylene, asymmetrical methylethyl ethylene,

causing simultaneous condensation 'of some of the oleines present. We have found that due to this effect, the yields of alcohol obtainable by sulpha tion methods from mixtures of hydrocarbons containing diolenes are lower than those obtainable from material which is free from dioleflnes. This phenomenon has been reported by Fritzche, Chemische Industrie, 35, 638 (1912) and other investigators on various similar hydrotrimethyl ethylene and isoprene, with lesser quantities of higher oleflnes. This fraction will be hereinafter identified as the 5-carbon atom fraction. a

The frststep after this fractionation is the removal of diolenes from each fraction. Cyclopentadiene, if present, may be removed'from the 5-carbon atom. fraction by'condensing the hydrocarbons to liquid'form and dimerizing this substance to dicyclopentadiene. This can be done by allowing the liquid hydrocarbons to stand for-"a long period of time, or by heating the liquid under pressure for a few hours. The dimer has a higher boiling point than the balance of the hydrocarbons of the S-carbon atom fraction and may be separated therefrom by fractional distillation at a reduced pressure. We

prefer to remove the cyclopentadiene as a step incidental to the flrst physical separation inasmuch as it has been found convenient to fractionate the higher boiling hydrocarbons at increased pressures and at a fairly high temperature. As a result, the cyclopentadiene is dimer--A ized and falls into the fraction containing lthe aromatic hydrocarbons in the initial fractionation. Dicyclopentadiene may be easily separated from these compounds by distillation at a reduced pressure. 'I'he isolated dimer can be converted to the original cyclopentadiene by distilling the dimer at atmospheric pressure.

The next step in the procedure is the remo of 'diolenes, other than cyclopentadiene, from the separate fractions in a form from which they may be easily recovered, and in a manner which does not destroy the oleflnes in the fractions.

The 4-carbon atom fraction is treated to reformation of the monomeric, soluble, crystalline sulphur dioxide addition product of the diolefine. An example of such an agent is sulphur chloride.

This may be conveniently ac-l from 45% or 55% to 65% concentration may be used. but a concentration of about 60% is preferred.` The conditions of sulphation. such as the temperature and the time of reaction. will vary with the strength of the acid. In general. temperatures below C., for `instance in the range of 10' to 35 C., are suitable.. Less concentrated acid requires higher temperatures and longer reaction times than strong acid. Typical conditions for the absorption of a diolenne-freed 4-carbon atom fraction are as follows: 11.92 kilograms of a 4-carbon atom fraction in the liquid state containing 45.5% of butane, 22.3% isobutylene 'and 32.3% of butenes 1 and 2 was continuously agitated with 17.72 kilograms of 61% sulphuric @cid `.for four hours at an average temperature ofabout24 C. Attheendofthistimetheunabsorbed hydrocarbons were removed. This quantity of'the fraction was 9 .74 kilograms and it contained 0.7% of isobutylene, 40.9% of butenes l and 2 and 54.8% of butane. The liquor formed contained tertiary-butyl sulphate produced by the action of the acid on the isobutylene. From the hydrolysis of the tertiarybutyl sulphate liquor. so prepared, 2.38 of tertiary-butyl alcohol was obtained. This corresponds to an overall tertiary-butyl alcohol yield of 67.7% based on the total amount of isobutylene in the original fraction. oran efliciency of 95.4% based on the original amount of isobutylene minus the amount recovered. In this sulphation the only by-product was 132 grams of oil. Instead of converting the tertiary-butyl sulphate into alcohol. it may be utilised to produce poly- Typical conditions for carrying out this removal 35 mers. such ndi-isobutylene. if desiredare as follows: 6.8 kilograms of a 4-carbon atom fraction containing about 15% of butadienesvere placed in a 20 liter autoclave to which was added 6.8 kilograms of sulphur dioxide and 30 cc. of

sulphur chloride. 'I'he autoclave was then heated o to 100 C. for 18 hours, the internal pressure being about 27.5 atmospheres. This treatment converted about 80% of the butadiene to the monomeric, soluble, crystalline addition product. The contents of the autoclave were charged into a 40 liter still and heated to about 70 C. The distillate was collected in a brine-cooled receiver and was allowed to stand at room temperature for two weeks in large steel cylinders. This completed the conversion .of the butadiene to the sulphur dioxide addition product. 'Ihe contents of the cylinders was redistilled and the distillate was passed through two scrubbers containing 16% NaOH into brine-cooled receivers. This distillate was the-olefine-bearing 4-carbon atom fraction and contained less than 0.5% butadiene.

The butadiene-sulphur dioxide addition product was allowed to collect in the kettle of the still. It may be decomposed by heating, first to about 95 C., most of the sulphur dioxide being boiled off, and then to about 120 C. The gas is scrubbed to removev sulphur dioxide, dried and cooled. This gives a gas which is largely butadiene. The only by-product of this process is an insignicant amount of tar which collects in the kettle of the still. Diolenes other than cyclopentadene may be removed in a form by which The 4-carbon atom hydrocarbons remaining after the nrst acid treatment are then treated with more concentrated acid to form secondaryalkyl sulphates. Acid varying from or 70% to 95% concentration may be used according to the conditions of time and temperature which are employed. In general, temperatures below 35 C.. and in particular, temperatures of less than 20 or 25 C., are suitable. Sulphuric acid of about strength, and a temperature of about 15 C. is preferred.

The following data illustrate the acid treatment .of a dioienne-freed 4-carbon atom fraction which had been previously treated with less concentrated sulphuric acid whereby most ofthe isobutylene was converted io tertiary-butyl sulphate: 11.36 kilograms of a mixture of hydrocarbons in the liquid state containing 1.5% of isobutylene, 43.9% of butenes 1 and 2 and aboutA 54.5% of butane was vigorously agitated with 15.9 kilogram! of 76.5% sulphuric acid. Thaaction time was 5 hours and the average x perature-of the reaction was about 15 C. At the end of this time the unreacted hydrocarbons, consisting chiefly oi' butane, were removed, their amount being 7.72 kilograms. The secondaryalkyl sulphate liquor which was obtained was hydrolysed and 3.86 kilograms of secondary-butyl alcohol were obtained. This represents an overall yield of 57.9% based on the total amount of butenes 1 and 2 at the beginning of the'treatment. The alcohol formed from the quantity absorbed less the amount recovered was- 86.6% oi the theoretical. In this step 477 grams of oils were formed as a by-product.

The description of the process subsequent to the preparingA of the two hydrocarbon fractions and the removal of cyclopentadiene from the 5- carbon atom fraction, has been contlned to. a 4-carbon atom fraction. The treatment of the -carbon atom fraction is carried out in like manner, first with sulphur dioxide and sulphur chloride to remove isoprene and diolennes other than cyclopentadiene from the fraction. and then with successive batches of sulphuric acid to form tertiary and secondary-alkyl sulphate liql 3 isfactory yields of4 alcohols from the alkyl sulphates.

uors from which amyl alcohols may be produced. f

In the treatment for the removal of dioleilnes from the -carbon atom fraction the reaction between the hydrocarbon and sulphur dioxide can be carried out with a lower temperature in the the 4-carbon atom fraction as follows: the dioletine-containing 4-carbon atom fraction obtained by the initial fractionation was iirst treated with sulphuric acid to form tertiary-alkyl sulphates from the isobutylene in the manner described. The hydrocarbons remaining after this treatment The foregoing conditions and proportions are obviously subject to modification andl such variations are included within vthe scope of the invention.

We claim:

1. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures which includes the steps of separating from said mixture at least one fraction'which is substantially free from hydrocarbons having less than four carbon atoms, treating said fraction to remove diolefines without lessening the olefine content of said fraction, said dioleflnes being removed in a form from which they are easily recoverable,

treating the diolefne-freed material with about 45% to 65% sulphuric acid to form a tertiaryalkyl sulphate liquor and treating the hydrocarbon residue from said treatment with about 70% to 95% sulphuric acid to form a secondaryy alkyl sulphate liquor.-

were/then treated with sulphur dioxide to re-v move butadiene in the manner described in Example I. The diolene-freed hydrocarbons, consisting mainly of butaneand butenes 1 and 2, were then treated with acid to form secondaryalkyl sulphates as before. In this modification of the process there was no change in the treatment of the -carbon atom fraction.

It is possible to make this variation in treat.-

ing the 4-carbon atom fraction because butadiene falls between isobutylene and the other butenes 2. A process for preparing alkyll sulphate liquors from cracked hydrocarbonl mixtures which includes the steps of separating from said mixture at least one fraction which is substantially free from hydrocarbons having less than four carbon atoms, treating said fraction to remove diolefines without lessening the oleflnecontent of said fraction, said diolenes being removed in a form from which they are easily recoverable, treating the diolefine-freed material with about 45% to 65% sulphuric acid at a in the order of their reactivity with sulphuric acid. 'I'his mode of procedure is not preferred because a less clean-cut separation of the hydrocarbons is secured.

The process may be modified in other respects. For example, it may be advantageous to remove only a portion, for instance, threefourths of the olefines in one treatment with sulphuric acid.l 'I'his leaves a residue which is temperature below about 35 C. to form a tertiary-alkyl sulphate liquor and treating the hydrocarbon residue from said treatment with about 70% to 95%, sulphuric acid at a temperature below -about 35 C. to form a secondary-alkyl sulphate liquor.

3. A process for preparingalkyl sulphate liqours from cracked hydrocarbon mixtures which includes the steps of separating from said mixture at least one fraction which is substantially rich in' parailln hydrocarbons and which maythenv be treated in a separate step vto reduce the oleflne content to negligible proportions. This residue having most of the olenes removed may be fractionated to remove most of the par-` aiins, and the concentrated oleiine portion may then be admixed with fresh hydrocarbons in the sulphating process.. 'I'his procedure is particular- 1y applicable to the second sulphation step wherein secondary-alkyl sulphates are formed, but it may be applied, in part, to the formation of tertiary-alkyl sulphates.

It-will be seen that each mode of procedure set forth herein provides a novel process for the formation of alkyl sulphates. In each case diolene hydrocarbons are removed and recovered free from hydrocarbons having less than four carbon atoms," treating said fraction to remove diolenes without lessening the oleflne content of said fraction, said diolefines being removed in a form from which they are easily recoverable, treating the diolefine-freed material with approximately 60% sulphuric acid to form a tern tiary-alkyl sulphate liquorand treating the hydrocarbon residue from said treatment with approximately 75% sulphuric acid to form a' secondary-alkyl sulphate liquor. y

4. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures which includes the steps of separating from said mixbefore the hydrocarbon mixture is treated with sulphuric acid of a strength suilicient to affect the diolenes. This process for sulphating `diolenefreed material possesses distinct advantages over prior methods. It is more economical due to the fact that all the constituents of a hydrocarbon mixture are recovered in usable and valuable form, and because it results in more sattures at least one fraction which is substantially free'from hydrocarbons having less than four carbon atoms, treating said fraction to remove diolefines Without lessening the olene content of said fraction, said diolenes being removed in a form from which they are easily recoverable, treating the dioleflne-freed material with approximate1yv55% to 65% sulphuric acid at a temperature of about 10 to 35 C. to form a tertiaryalkyl sulphate liquor and treating the hydrocarbon residue from said treatment with approximately sulphuric acid at a temperature less than about 20 C. to form a secondary-alkyl sulphate liquor. n

v5. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures which includes the steps of separating from -said mixturesA at least one fraction which'is substantially free from substances more volatile than hydrocarbons having less than iour carbon atoms and from substances less volatile than hydrocarbons having ilve'carbon atoms, treating said fraction 'to remove dioleiines without lessening the oletine content of said fraction, said diolenes being removed -in a form from which they are easily recoverable, treating the dioleilne-ireed' material with about 45% to 65% sulphuric acid to form a tertiary-alkyl sulphate liquor and treating the hydrocarbon residue from said treatment with about 70% to 95% sulphuric acid to form a secondary-alkyl sulphate liquor.

6. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures which includes the steps of separating from said mixtures at least one fraction which is substantially free from substances more volatile than hydrocarbons having less than four carbon atomsy and from substances less volatile than hydrocarbons having five carbon atoms, treating said fraction to remove diolenes without lessening the oleine content of said fraction, said diolenes being removed in a iorm from which they are easily recoverable, treating the dioleiine-freed material with about 45% to 65% sulphuric acid at a temperature below about 35 C. to form a tertiaryalkyl sulphate liquor and treating the hydrocarbon residue from said treatment with about '70% to 95% sulphuric acid at a temperature below about -25 C. to form -a secondary-alkyl sulphate liquor.

7. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures which includes the steps of separating from said mixtures at least one fraction which is substantially free 'from substances more volatile than hydrocarbons having less than four carbon atoms and from substances less volatile than hydrocarbons having five carbon atoms, treating said fraction to remove dioleiines without lessening the olefine content of said fraction, said dioleiines being removed in a form from which they are easily recoverable, treating the dioleiine-ireed material with approximately 55% to 65% sulphuric acid at a temperature of about to 35 C. to form a tertiary-alkyl sulphate liquor and treating the hydrocarbon residue from said treatment with approximately 75% sulphuric acid at a temperature below about 20 C. to form a secondaryalkyl sulphate liquor. f

8. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures which includes the steps of separating from said mixture a fraction consisting substantially of four carbon atom hydrocarbons, treating said fraction with about 45% to 65% sulphuric acid to form a tertiary-alkyl sulphate liquor, treating the hydrocarbon residue from 'said treatment to remove dioleilnes without lessening the olene content of said fraction, said dioleiines being removed in a form from which they are easily recoverable and treating the dioleiine-freed material with about '70% to 95% sulphuric acid to form a secondary-alkyl sulphate liquor.

9. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures containing eyclopentadiene which includes the steps of separating from said mixture at least one i'raction which is substantially free from hydrocarbons having less than four carbon atoms, treating said fraction to remove diolenes without lessening the oleilne content of said fraction by dimerizing cyclopentadiene and removing dicyclopentadiene and by treating said fraction with about 70% to 95% sulphuric @cinto faim" a secondary-alkyl sulphate liquor.`

10. A process for preparing alkyl sulphate liquors from cracked hydrocarbon mixtures containing cyclopentadiene which includes the steps of separating from said mixture at least one fraction which is substantialLv free from hydrocarbons having less than four carbon atoms, vtreating said fraction to remove dioleilnes without lessening the oleilne content of said traction by dimerizing cyclopentadlene and removing dicyclopentadiene and by treating said fraction with SO: in the presence oi' a halogen-containing body to form a crystalline, soluble SO: addition product of the diolenes and removing said addition product, treating the diolene-freed material with about 45% to 65% sulphuric acid at a temperature below about 35 C. to form a tertiary-alkyl sulphate liquor and treating the hydrocarbon residue from said treatment with about 10% to 95% sulphuric acid at a temperaturebelow about 35 C. to form a secondary-alkyl sulphate liquor.

l1. A process for preparing alkyl sulphate liquorsfrom cracked hydrocarbon mixtures which includes the steps of separating from said mixture an oleiine fraction comprising essentially oleilnes of four carbon atoms, treating said fraction to remove dioleiines without lessening the oleiine content oi said fraction, saiddioleiines being removed in a form from which they are easily recoverable, treatingy the dioleiine freed material with about 65% sulphuric acid to form a tertiary alkyl sulphate liquor and treating the hydrocarbon residue from said treatment with about r15% sulphuric acid to fonn a secondary alkyl sulphate liquor.

12. Process of sulphating olefines occurring in a mixture of hydrocarbons derived from the cracking of mineral oil and containing predominantly oleilnes of four carbon atoms including tertiary olenes and diolenes, which comprises selec- 1 tively removing the unpolymerized diolenes from said mixture, reacting the diolene freed mixture with aqueous sulphuric acid not exceeding about 65% strength at about 25? C.to sulphate the tertiary oleflnes and sulphating the remaining olenes with sulphuric acid of higher than '10% Istrength at a temperature below 35 C.

13. Process of treating oleflnes in a mixture of hydrocarbons containing mono and dioleiines, which comprises separating a fraction, the olefine content oi' which consists predominantly of butadiene and butene, selectively removing'unpolymerized butadiene from said fraction, thereby forming a remanent fraction containing iree butene and thereafter sulphating the butene in said remanent fraction.

14. Process of treating voleiines in a mixture of hydrocarbons consisting predominantly of oleiines, which comprises separating a fraction consisting predominantly of butadiene and butene, selectively removing l. unpolymerized butadine from said fraction, thereby forming a` remanent fraction containing free butene and thereafter sulphating the butene contained in said remanent fraction.

GRANVILLE A. PERUNS.

CERTIFICATE 0E CORRECTION. s' Patent No. 2,271,092. January 27, 19h2.

GRANVILLE A. PERKINS, ET AI..

It is hereby certified that error appears in the -printed specification 4ofthe abovevnumbered patent .requiring-correction as follows: Page 1|., second colwnn, line 70, claim 1h, for "butadine" read -buta.diene; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent. Office.

signed and sealed this auth day of March, A. D. 19h2.

- Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

